The light yellow area is public area outside the ticket gates. From the Sobu Line/Narita Express platform you come up the elevators or escalators to the pale blue area. Then there is another escalator (which is quite short though it looks longer on the map) to go up to the pink area which is the main concourse. Depending on the time of day you could be mixing with commuters and I always found going up the last escalator with heavy luggage something of a challenge.

The pink area is more or less on the street level but you wouldn't know once you are inside the station because the whole area is covered and could very well be in the basement. If you don't see the signs for the Yaesu Exit follow the signs for Daimaru Department Store which occupies more or less the whole length of the station on the Yaesu side.

Here is Google Street View of the crossing with the Mizuho Bank in front of you.